5.8 should be returned for 5.8.x dependencies

[haarg]

If a minimum version like v5.8.8 is specified, it should include v5.8 in the output.

When using the output of this action, generally the latest patch version will be used. So a v5.8 output will generally result in testing on perl 5.8.9. Given this assumption, it makes sense to include v5.8 for any v5.8.x version.

For most perl versions the patch version isn't really important. But anything depending on 5.8 versions will often depend on specific versions to avoid bugs. It's common to declare a dependency on perl 5.8.1 for its sane Unicode handling, or 5.8.5 where most of the Unicode bugs were fixed.